Systems used to produce capsules containing medicine or other quantities of dosed material often comprise multiple stations configured to perform individual tasks needed to form the capsules. In certain embodiments, empty capsules are initially placed into a hopper. These capsules consist of a capsule body and cap. Empty capsules can then be rectified so that they are all in the same position, e.g. cap up and body down. The capsules can then be transferred from the rectification station to a transfer block.
In certain systems, the transfer block transfers the capsules from the rectification station to a cap disk or plate. There may also be a transfer block that moves between the cap plate and body plate. The capsule bodies can sucked down through this transfer block and deposited in the body disk. In specific systems, the caps are larger in diameter then the bodies, and are retained in the cap disk, causing the caps and bodies to be separated. In certain systems, the capsules can index past a station that removes any capsules where the bodies did not separate from the caps.
In some systems, the capsules may also index past a sensor that looks for missing caps or bodies. This will then determine if that segment of capsules will be filled or rejected. If any caps or bodies are missing the segment will not be filled and they will be sent to rejection when they reach the ejection station. Capsules may then index to the filling station where they are filled unless otherwise marked for rejection.
In specific systems, the capsules then index to the closing station. In this station, the capsule bodies and caps are joined together to form a capsule. In certain systems, closing pins push the capsule bodies into a closing block from the body plate. The closing block and closing pins can then move together up to the cap disk. In certain systems, the capsule bodies are initially towards the bottom of the cylinder or conduit that holds them in the closing block.
In certain systems, the closing pins can continue to move towards the cap plate until the capsule bodies are pushed into the capsule caps, thereby closing and locking the capsule. Capsules that are successfully formed continue to index around until they are pushed out at the ejection station.
In some existing systems, there is typically no way for air in the cylinder or conduit that is trapped between the capsule body and cap to escape as the body is moved towards the cap. The increase in pressure can contribute to capsules popping open or leakage on liquid filled capsules before the seal can be applied. This in turn soils the equipment and creates a cascade of additional problems that eventually cause the system to shut down. As a result, costs may be increased due to system downtime, higher maintenance, and lower product yield. A need therefore exists to relieve the pressure created when the capsule body and cap are brought together.